Artificial gravity meeting zero gravity

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Discussion Overview

The discussion revolves around the concept of artificial gravity in a rotating space station, specifically focusing on the dynamics experienced by an individual moving between a rotating hoop and a stationary hoop in a low gravity environment. Participants explore the implications of motion, inertia, and the effects of acceleration on perceived weight and gravity.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant proposes a scenario involving two hoops, one rotating to create artificial gravity while the other remains stationary, questioning the effects on a person transitioning between them.
  • Another participant clarifies that artificial gravity in a spinning space station is due to inertia and not a true gravitational force, emphasizing the need for contact with a surface to experience any force pulling them down.
  • There is a discussion about how a person moving at high speeds on the outer wall of the space station could return to a state of weightlessness by accelerating in different directions relative to the wall.
  • Some participants suggest that moving in the direction of the station's rotation would increase perceived weight, while moving against it would decrease weight, leading to complex dynamics of motion.
  • One participant questions how reduced weight would interact with lift in a hypothetical plane flying within the rotating station, seeking to understand the trajectory and dynamics involved.
  • Another participant notes that achieving weightlessness would depend on the rotational speed of the space station not exceeding the individual's running speed.
  • There is a mention of the potential for an airplane in a large space station to experience excess lift, which would need to be countered to maintain stable flight.

Areas of Agreement / Disagreement

Participants express differing views on the nature of artificial gravity and the dynamics of motion within a rotating space station. There is no consensus on the implications of these dynamics, and multiple competing perspectives remain throughout the discussion.

Contextual Notes

Limitations include assumptions about the environment, the definitions of artificial gravity versus inertia, and the mathematical relationships governing motion and perceived weight in a rotating system. Unresolved questions about the dynamics of lift and weight in various scenarios are also present.

  • #31
Funny that these same calculations result in a counter-proof to the hollow-Earthers (Koreshian cosmogony):
If we did inhabit the inside surface of a hollow sphere the size of the Earth, the centripetal acceleration at the equator would be over 3G...
 
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  • #32
dbell5 said:
Funny that these same calculations result in a counter-proof to the hollow-Earthers (Koreshian cosmogony):
If we did inhabit the inside surface of a hollow sphere the size of the Earth, the centripetal acceleration at the equator would be over 3G...

So there is more force than just gravity holding the planet together?
 
  • #33
dbell5 said:
Funny that these same calculations result in a counter-proof to the hollow-Earthers (Koreshian cosmogony):
If we did inhabit the inside surface of a hollow sphere the size of the Earth, the centripetal acceleration at the equator would be over 3G...

How do you figure 3Gs?

If that were true, it would apply to the outer surface as much as the inner surface. What you are suggesting is that, standing on the outer surface of the Earth, I am experiencing a 3G pull away from the Earth!
 
  • #34
DaveC426913 said:
How do you figure 3Gs?

If that were true, it would apply to the outer surface as much as the inner surface. What you are suggesting is that, standing on the outer surface of the Earth, I am experiencing a 3G pull away from the Earth!

Huh! That would appear to be so! (Actually, 2G away, since the Earth's field is 1G inwards at the surface, vs. 0G inside a hollow shell.)

OK, here's how I got there:
a = v^2/r
Circumference of Earth is about 41,000 km, or 41e6 meters
Rotation is once in 86,400 seconds, for a tangential velocity of about 474 m/s.
Radius is about 6,500 km, which is where I went wrong - I divided by 6,500, not 6.5e6.
I got 34 m/s^2, should be 0.034 m/s^2

OK, so we're in no immediate danger of flying off into space!

Dave
 
  • #35
A corollary to the above that I never thought of is that, even if the Earth were a perfect, homogeneous sphere, and ignoring the bulky clothes, I'd weigh nearly 5 pounds more at the poles than I do here at 37°N!
 
  • #36
dbell5 said:
A corollary to the above that I never thought of is that, even if the Earth were a perfect, homogeneous sphere, and ignoring the bulky clothes, I'd weigh nearly 5 pounds more at the poles than I do here at 37°N!

So that's why Santa is so heavy.
 

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